Gear head assembly



Aug. 3, 1965 F. l.. DAHL ET AL GEAR HEAD ASSEMBLY 2 Sheets-Sheet 1 Filed NOV. 16, 1961 Aug. 3, 1965 F. L. DAHL ET AL GEAR HEAD ASSEMBLY 2 Sheets-Sheet 2 Filed Nov. 16, 1961 United States Patent O 3,193,023 GEAR HEAD ASSEh/BLY Frederick L. Dahl, Ringoes, NJ., and .lames H. Hohe,

Bedminister, and Staniey Cohen, Eikins Park, Pa., as-

siguors to Kollsman instrument Corporation, Elmhurst,

NSY., a corporation of New York Fiied Nov. 16, 1961, Ser. No. 152,731 4 Claims. (Ci. 74-409) y[with great accuracy by electrically positioning an armature to match the position of another armature, any inaccuracy in the mechanism which mechanically responds kto the position of the iirst armature or in the mechanism which positions the second armature will destroy the effectiveness of the synchro system.

In particular, in the assembly of gears, while the gears and their shafts may be accurately constructed, great difculty arises when the shafts are aligned owing to the fact that kbearing openings or supports for the gear shafts must also be accurately aligned. This problem has contributed greatly to the expense of gear head assemblies for accurate output and has in fact made the gear head far more costly than it should be in reiation to the cost of other components.

My invention contemplates the construction and arrangement of a gear head assembly wherein the parallel end plates of the cage supporting the gears are machined or cast integrally with a plurality of legs which space them appropriately and ensure that the parallel arrangement will be permanently maintained. By making the cage in one piece, subsequent machining operations are materially reduced since the end plates can be machined in a single set-up thereby assuring concentricities, alignments and parallelism within close limits. After the required surfaces have been machined, the bearing holes may be bored and support and other openings may be made or tapped as desired. The precision of the boring operation, which now can be performed in the same set-up, will largely eliminate back-lash in the gears.

Further, the one piece construction of the cage eliminates the inherent weakness of plate and post construction and the difliculties in manufacture and assembly. In all sizes of gear head assemblies, this arrangement permits load capabilities two to three times the load capabilities of comparable designs. In a size l frame this gear box y will withstand 50 in. oz. torque continuously and 100 in.

oz. momentary torque.

The primary object of my invention is the provision and arrangement of a novel gear head assembly.

A corollary object of my invention is the arrangement of a gear cage wherein the end plates are integral with the spacing members.

A further object of my invention is the provision of a gear cage wherein exact concentricities, alignments and parallelism of the end plates and the gears will be maintained.

Another object of my invention is the provision of a gear head assembly having a gear cage supporting gears with a minimum of back-lash.

The foregoing and many other objects of my invention will become apparent in the following description and drawings in which:

Cir

3,198,028 Patented Aug. 3, 1965 FIGURE l'is a View partly in cross-section of my novel gear head assembly taken from line 1-1 of FIGURE 2.

FIGURE 2 is an end view of my novel gear head assembly.

FIGURE 3 is a fragmentary view in cross-section corresponding to the lower left corner of FIGURE 1 but taken on a different radius, on line 3-3 of FIGURE 2.

Referring ot the figures, my novel gear head assembly comprises a housing 10, a head member 11 and a cage 12. The cage 12 comprises the end plates 13, 14 which are parallel to each other and secured and spaced by three legs 15, 16 and 17, in this instance, two of which, legs 15 and 16, may be seen in FIGURE 1. Legs 15, 16 and 17 are cast or machined integral with end plates 13, 14.

This integral arrangement provides the assurances of concentricity, alignment and parallelism previously pointed out and provides a unitary structure where the bearing diameters vin both end plates 13, 14 may be bored in the same set-up thereby assuring absolute accuracy.

Thus, the bearing openings for shafts 19, 23, 26, 29, 32, 35 and 3S may be bored in the same set up in plates 13 and 14.

Keeping in mind that the particular number of gears and their particular relationship to provide the desired output torque and speed may vary from application to application, the specific gear train here used will be briefly described preliminary to describing the shaft mountings which are made possible -by my invention. Input shaft 19 (which may be the output shaft of a pinion driving motor) entering cage 12 through opening 20 in end plate 13 has gear teeth 21 which mesh with and drive gear 22 on shaft 23. Shaft 23 carries gear 24 which drives gear 25 on shaft 26; shaft 26 carries gear 27 which drives gear 28 on shaft 29; shaft 29 carries gear 30 which drives gear 31 on shaft 32; shaft 32 has gear 33 which drives gear 34 on shaft 35; shaft 35 has gear 36 which drives gear 37 von shaft 38. Shaft 38 is extended beyond its bearing 40 in plate 14 to provide the cantilevered gear 41 which drives gear 42 on output shaft 43.

Shafts 29 and 33 are clearly visible in FIGURE 1. The bearings 45, 46 of shaft 29 and bearings 40, 47 of shaft 3S are clearly shown as mounted in aligned openings in opposite end plates 13, 14; these openings are originally formed in perfect alignment by reason of the integration of the end plates 13, 14 and legs 15, 16 and 17 as above described. The other shafts 23, 26, 32, 35 are mounted in similarly aligned bearings. The various gears are of course off-set along their respective shafts so that the gears are in appropriate planes to mesh only with their mating gears and not to engage other gears in the gear train.

The cylindrical housing 10 is provided with an opening of internal diameter Stjust suicient to receive and position the plates 13 and 14 of cage 12. This opening is bored exactly concentric with the opening 51 of the housing 1t) which is bored concentric with the bearing hole of the drive motor (not shown) from which drive pinion or shaft 19 emerges or to a mounting fiange (not shown) on the drive motor; .by this means concentricity is maintained between gear cage 12 and motor pinion 19 in order to provide proper engagement between motor pinion 19 and gear 22.

The gear head member 11 carrying output shaft 43 in bearing 52 -is secured to the housing 10. Head member 11 is provided with the cylindrical extension 53 which enters the housing 1t? and is slightly eccentric therewith to provide for a backlash adjustment, as fully set forth below. Extension 53 also provides a recess 54 for gear 42, and also defines iiange 55 which bears against the edge of the housing 1t). The method tof securement of head member 11 to the housing provides the major adjustment means for reducing or obviating backlash in the entire gear train.

This is so because the` largest component of backlash occurs at connection between gears 41, 42.

Let Btn'r equal the total backlash of the system and Bl, 2, 3 N=the linearV backlash at each mesh, with B6 the backlash atthe output stage, P1 -2-3 .f".` N ::the Vpitch diameter of the pinions and G1-2 3.; .N :the pitch diametersl ofthe gears.l

Then

60 to plate .14 ofcagei12.V The three screws used pass through longitudinal openings 61 in yhead member 11 into tapped openings 62 in the plate 14 'of the cage,12. Y The assembly of head member 11 and cage 12 is theninserted into housing 10. n By rotating the cage l12 andA head member Y'11 with equal backlash atl each mesh rand respect to the longitudinal axis of the housing, whereby said shaft carried by the head and its gear are eccentrically positionable'with respect to said longitudinal axis of the Vhousing and the cagejadjustable Vconriectingf'n'ieans for permitting a continuous rotatable adjustment between said housing member `and said cage Within a predeter- .minedangular limit to adjust for backlash between said output drive gear and the gear carriedby the shaft in said `head member;-and means forvlocking the cage and head to secure said adjustment. j

t 2. A gear head assembly comprising a cylindrical housing; a gearrcage in a tirsty cylindrical formation of said housing and ahead member supported `in-a second cylindrical formation. of said housing, a third cylindrical housing formation, the longitudinal axes of said third cylindricalho'using formation and said Vgearcage coinciding;

saidgear cage having alpair o'f parallel [platesintegrally connectedto a plurality of spacer members extending between the plates; 'openings in said plates, bearings Ain said openings; each ofsaid openingsin oneplate being aligned with lanopening inthe opposite plate; a plurality of gear carrying shafts -between said plates; said shafts each being respect to each o ther, thevbacklash between gears 41v and, Y

42 is compensated. Therelationship'between 'the rdiameters of holes61 in the head member and the diameters ro'f screws 60`will determine ythe Vextent of rotational adjustment whichmay .be made.Y When the adjustment is made, the screws60 are tightened against .the lock washers 68 and the adjustment secured@ Self tapping screwsk 65 are then-,inserted in'openings; 66 of thehousing 10 and tight ened in 4annular grooves 67 Yof head member extension 53 to secure theassembly inplace. l v Y j By this means a simplified gear train is pnovided with accuratebearing arrangements, accurate alignment, concentricity and parallelism as well as a simplified easily tions and variations of lour invention willnow be obvious to those skilled in theart, we prefer to be bound,` not byV the Vspecific Vdisclosures herein contained, but only by the appended claims. Y Y Y f The embodiments ofthe Yinvention inl which an exclusive privilege or property is claimed are defined as follows: Y 1. A Vgear head assembly comprising a cylindrical hous ing; a gear cage lin a iirsticylindrical yformation yof said housing anda head member supported in a second cylin drical formation of saidhousing, the longitudinal axes of said housing and gear cage coinciding; said gearcage having'afpair of parallel plates integrally connectedto'a pluralityof spacer members extending between the plates; openingsA in said plates, bearings in said openings; each of said openingsin one plate being aligned with an open-` ing in the opposite plate;`a plurality of gear carrying shafts betweensaid plates; said shafts each being rotatably supported in opposite aligned openings and an additional` l opening in one ofthe platesto receive a driving member; one of said shafts extending beyond the opposite plate to provideV an.output drive gear; an additional rotatable shaftncarried by the head member; a gear on'the .portion of said shaft extending toward said cage; said outputdrive gear meshing with said gear on the shaft carried by said head member; the said lastmentioned shaft extendingv beyond said'head'm'ember. to provide an output drive; said: second cylindrical formationbeing slightly eccentric with rotatably supported in opposite aligned openings ,and an litio'nal opening inione of the plates to receive. a driving nember; 'said additional -openingbeing adjacentsaid third cylindricalhousing. formation and in concentricr alignment therewith; one-of said shaftsextendingbeyond the-oppo-Y site plate torprovide anbutput drive gear; an additional rotatable shaft carried'by'thehead member; .a gear on ing', whereby,` said shaft carried byo'the head and its gear are eccentrically positionable with respect to. said longitudinal axis ofthe housingand the cage; adjustable connecting means for permitting a continuous rotatable adjustment between said housing memberl and saidcage within a pref determined angular limitto adjustfor. backlash between said outputdrive gear. andthe gear carried-by they shaft in said head member;.and means for locking the cage and head to secure said adjustment.

. 3. A gear head assembly as setforth inl claim 1, Wherein Vsaid -adjustableconnecting means comprises angularly separated screwfrneans transversely extending between oversized openings in one 'of said cage or head members,

and snugly mating with the other ofsaid cage or head members; the spacing betweenA saidscrew means and oversized opening defining said predetermined angular limit. 4."A gear head assemblyy asset forth in claim 3 vwhereL 'y in said'meansfor lockingcomprise anannular. groove-in said' headmember, in registry relationship with means entering said second cylindrical opening via-angular separatedyopeningsin said housing extendinggenerally.along k1,320,061 Y8/31 Riagg 'I4-801 3,011,358; 12/61 Moore '74-,409 3,091,131 5/63 Mentally 74-606 DON A.WAITE; Primary Examiner.l

' BRQUGHTON GQDURHAMExaminr'. 

1. A GEAR HEAD ASSEMBLY COMPRISING A CYLINDRICAL HOUSING; A GEAR CAGE IN A FIRST CYLINDRICAL FORMATION OF SAID HOUSING AND A HEAD MEMBER SUPPORTED IN A SECOND CYLINDRICAL FORMATION OF SAID HOUSING, THE LONGITUDINAL AXES OF SAID HOUSING AND GEAR CAGE COINCIDING; SAID GEAR CAGE HAVING A PAIR OF PARALLEL PLATES INTEGRALLY CONNECTED TO A PLURALITY OF SPACER MEMBERS EXTENDING BETWEEN THE PLATES; OPENINGS IN SAID PLATES, BEARINGS IN SAID OPENINGS; EACH OF SAID OPENINGS IN ONE PLATE BEING ALIGNED WITH AN OPENING IN THE OPPOSITE PLATE; A PLURALITY OF GEAR CARRYING SHAFTS BETWEEN SAID PLATES; SAID SHAFTS EACH BEING ROTATABLY SUPPORTED IN OPPOSITE ALIGNED OPENINGS AND AN ADDITIONAL OPENING IN ONE OF THE PLATES TO RECEIVE A DRIVING MEMBER, ONE OF SAID SHAFTS EXTENDING BEYOND THE OPPOSITE PLATE TO PROVIDE AN OUTPUT DRIVE GEAR; AN ADDITIONAL ROTATABLE SHAFT CARRIED BY THE HEAD MEMBER; A GEAR ON THE PORTION OF SAID SHAFT EXTENDING TOWARD SAID CAGE; SAID OUTPUT DRIVE GEAR MESHING WITH SAID GEAR ON THE SHAFT CARRIED BY SAID HEAD MEMBER; THE SAID LAST MENTIONED SHAFT EXTENDING BEYOND SAID HEAD MEMBER TO PROVIDE AN OUTPUT DRIVE; SAID SECOND CYLINDRICAL FORMATION BEING SLIGHTLY ECCENTRIC WITH RESPECT TO THE LONGITUDINAL AXIS OF THE HOUSING, WHEREBY SAID SHAFT CARRIED BY THE HEAD AND ITS GEAR ARE ECCENTRICALLY POSITIONABLE WITH RESPECT TO SAID LONGITUDINAL AXIS OF THE HOUSING AND THE CAGE; ADJUSTABLE CONNECTING MEANS FOR PERMITTING A CONTINUOUS ROTATABLE ADJUSTMENT BETWEEN SAID HOUSING MEMBER AND SAID CAGE WITHIN A PREDETERMINED ANGULAR LIMIT TO ADJUST FOR BACKLASH BETWEEN SAID OUTPUT DRIVE GEAR AND THE GEAR CARRIED BY THE SHAFT IN SAID HEAD MEMBER; AND MEANS FOR LOCKING THE CAGE AND HEAD TO SECURE SAID ADJUSTMENT. 